#include <iostream>
#include <set>
#include <algorithm>

using namespace std;

void test()
{
    set<int, std::less_equal<int> > s;
    s.insert(10);
    s.insert(10);
    
    for (auto i : s)
    {
        cout << i << " ";
    }
    cout << endl;

    auto it = s.find(10);
    if (it == s.end())
    {
        cout << "End" << endl;
    }
    //find之类的也回判断错误
}

int main()
{
    test();
    return 0;
}
